The present invention relates to a method and system for controlling a network, and more particularly, to a method and system for a network having an IEEE 1394 hot plugging function.
A data communication system having an interface that complies with the IEEE 1394 standard includes a hot plugging function which permits new devices to be connected to an already active network. When a new device is connected, the system automatically reconfigures the network to recognize the new device.
A personal computer and peripheral equipment, such as a digital video camera and a color page printer, are each provided with an interface controller for transferring data in compliance with the IEEE 1394 standard. When an interface controller detects the connection of a new node (device) to its port (socket), the controller provides a reset command to each of the nodes in the network. In response to the command, the interface controller of each of the nodes connected to the network remaps the network configuration (topology), consequently reconfiguring the network.
However, the connection or disconnection of a device is often performed regardless of data whether data is being transferred between nodes. FIG. 1 illustrates an example of a network formed by a plurality of nodes 1-4. If a node 5 is newly connected to the node 1 while data is being transferred between the nodes 2, 4, the node 1 detects the connection of the node 5 and provides a reset command to each of the nodes 2-5. This resets all of the nodes 1-5 and interrupts and stops the data transfer occurring between the nodes 2 and 4.
For example, data is transferred by a plurality of packets in an interface complying with the IEEE 1394 standard. Thus, even if the transfer of data packets is interrupted, all of the data packets are transferred again upon restarting. This is because the receipt of the data packets which were interrupted during transfer cannot be confirmed. As a result, the transfer of data packets must be performed once more from the beginning.
It is an object of the present invention to provide a network control method and system that guarantees the transfer of data while enabling hot plugging.
To achieve the above object, the present invention provides a method for controlling a network having a configuration including a plurality of nodes. The method includes the steps of recognizing the connection of a new node to the network, determining whether a communication is being performed in the network prior to the recognizing step, completing the communication, and reconfiguring the network, which includes the new node, subsequent to completion of the communication based on the determination result.
A further aspect of the present invention provides a method for controlling a network having a configuration including a plurality of nodes. The method includes the steps of recognizing the connection of a new node to the network, determining whether communication is being performed in the network, interrupting the communication based on the determination result, reconfiguring the network including the new node, and restarting the interrupted communication.
Another aspect of the present invention provides an apparatus for controlling a network having a configuration including a plurality of nodes. The system includes a data transfer determination circuit for determining whether communication is being performed in the network. A reset control circuit, connected to the determination circuit, recognizes the connection of a new node to the network and reconfigures the network to include the new node, subsequent to completion of the communication based on the determination result of the data transfer determination circuit.
A further aspect of the present invention provides an apparatus for controlling a network having a configuration including a plurality of nodes. The system includes a data transfer determination circuit for determining whether communication is being performed in the network. A reset control circuit, connected to the determination circuit, recognizes the connection of a new node to the network and interrupts the communication based on the determination result of the data transfer determination circuit, reconfigures the network, which includes the new node, subsequent to the interruption of the communication, and restarts the interrupted communication.